基于基追踪分解算法的薄层波阻抗反演  

Impedance Inversion of Thin-bed Based on Basis Pursuit

作　　者：郝亚炬 文晓涛[1,2] 李忠[3] 李世凯[1,2] 李天[1,2] 

机构地区：[1]成都理工大学地球物理学院,成都610059 [2]成都理工大学地球探测与信息技术教育部重点实验室,成都610059 [3]川庆钻探工程有限公司物探公司技术发展中心,成都610213

出　　处：《科学技术与工程》2015年第33期10-17,共8页Science Technology and Engineering

基　　金：国家自然科学基金(41174115);联合基金项目(41562111)资助

摘　　要：为提高波阻抗反演的分辨率,将基追踪反演(basis pursuit inversion,BPI)方法用于地震阻抗反演。该反演方法将地层的顶、底反射系数视为一个奇对称脉冲对和一个偶对称脉冲对的线性组合。反演过程中将地震信号通过基追踪算法投影到子波与上述两类脉冲褶积形成的楔形模型库上,通过该投影值可求得每道的相对反射系数。得到相对反射系数剖面后,进行道积分即可得到相对波阻抗剖面。相比于传统的稀疏脉冲反演(sparse spike inversion,SSI),BPI结果不受初始模型的影响,可显著提高波阻抗反演对薄层的分辨能力。对合成信号的试算表明,BPI结果比SSI结果更好地识别了薄层信息。对珠江口盆地碳酸盐岩储层的实际地震数据的反演表明,BPI结果上的很多细节信息在传统SSI结果上无法看到。因此,BPI更适用于薄层波阻抗的反演。In order to improve the resolution of impedance inversion,basis pursuit inversion（ BPI） was performed to impedance inversion. The top and bottom reflectors of thin-bed were considered as a linear combination of even and odd impulse pairs. In inversion process,the seismic signal was decomposed to the convolution of wavelet and even and odd impulse pairs by basis pursuit decomposition algorithm. The reflection coefficient can be obtained by the decomposition coefficients. BPI is not affected by initial model,which is advance to sparse spike inversion（ SSI）. Synthetic tests suggest that the resolution of BPI can better resolve thin beds than SSI. Application to field data indicates that BPI results can show some details that are not readily seen on SSI results. In this case,BPI is more suitable for thin beds inversion.

关 键 词：基追踪反演 基追踪分解 稀疏脉冲反演 薄层波阻抗反演 楔形子波库 

分 类 号：P631.43[天文地球—地质矿产勘探]